Answer: It is the principle that matter cannot be created or destroyed.
Explanation:
<span> strictly speaking, a molecule has at least two atoms. ... Atoms with full valence electron shells are stable. Full Text[ edit ] The noble gases are a group of chemical elements that make up Group 18 on the periodic table.</span>
Fusion or melting is the phase change from solid to liquid.
The 1st law of thermodynamics doesn't specify that matter can be created nor destroyed, but that the total amount of energy in a closed system cannot be created nor destroyed though it can be changed from one form to another.
